Plastering - any tips?

[Rob Nicholson]

Renovation of the bathroom continues apace - the end is in sight!

Part of the renovation has been to extend the bathroom into the bedroom by about a foot in order to fit a full-size bath. This has created an alcove constructed as a stud wall covered in Wickes plasterboard.

The majority of the surfaces are going to be tiled so don't have to be made particularly "good". Except the ceiling of the alcove which, like the main ceiling, I'm considering painting.

Therefore, an area of about 1.5m x 0.5m needs plastering. I've done some bonding plasterwork but this is the first time I'm going to attempt finishing plaster. I've bought a bag of Wickes universal finishing plaster.

Anyone got any tips for this job?

o Should I try and make the mix quite thick as it's been applied to an upside down surface? o I was just going to treat the plasterboard with PVC glue - is this adequate? o As it's just a shim over the plasterboard that's required to hide the gaps, it can be a pretty thin layer - ok? o How long does a thin layer like this take to dry?

Thanks, Rob.

[Andrew Mawson]

Rob,

In my experience tiles directly onto plasterboard don't stay stuck for more than a year or so. The slight flexing of the plasterboard unbonds them. I have used Wickes cement based board intended for tiling in wet places and so far (4 years) it has stood the test of time.

Andrew Mawson

[Rob Nicholson]

Bit late for that! That part of the project is well and truely in place. Removing it would be a real problem...

I know that the plasterboard has to be well treated for the tiles to stick.

Cheers, Rob.

[mark]

I've cut and pasted this reply to a previous post as I'm sure the original poster wouldn't mind.

"If you've never tried it, don't touch the room. Get another sheet of plasterboard, some new multifinish or plasterboard plaster (as someone says, make sure it's fresh- the stuff sets in minutes if it's old and has to all come off again) and have a crack on the spare plasterboard. Make the mix up quite runny- I typically get a bucket of water and a drill-based mixer and add plaster until it's the consistency of whipped cream. A guy who used to do skimming for us told me once a common error is to make the mix too dry, and it becomes more difficult to work. Prepare the surface either by washing (to make wet) or PVAing (to seal) and then apply the plaster. The first challenge, particularly overhead, is to stop the stuff falling straight off again having not stuck to the surface :)

Assuming you get it all on, make reasonably smooth with the trowel and leave for a while. 10-20 minutes. It should now be firm but not set and you can use a wet trowel to ontinue smoothing the surface as far as necessary. Do it long enough and the final result (after drying) feels absolutely smooth with no grittiness.

After it's dry, look at an angle and see all the lumps you thought you'd smoothed out. If you're happy with the result, have a crack at the walls, one at a time. Make sure all the nails in the plasterboard are galvanised or otherwise rustproof, otherwise the heads will rust and expand and circles of plaster will pop off a few months down the line. If you're not happy, try it again- it improves with practise and you're better off wasting plasterboard that isn't on the wall.

-- Dr. Craig Graham, Software Engineer Advanced Analysis and Integration Limited, UK.

"Mark S.

[Andrew Mawson]

Round showers and baths is the real problem - the grout line develops tiny cracks - the water gets in, and off pops the tile !

Andrew

[RichardS]

You would do well to search this group on google groups, looking for posts on plastering by Andrew Gabriel.

Andrew took a plastering course a while ago, and has posted many good explainations and guides for plastering, including pitfalls to avoid.

My recent attempts at plastering were both satisfying and pretty successful, following advice gleaned from his posts - far more so than previous attempts.

When money and time permit (new business still sucking both up) I'm gonna go on one of them there plastering courses...

cheers Richard

-- Richard Sampson

email me at richard at olifant d-ot co do-t uk

[Rob Nicholson]

Fortunately, the new plasterboard isn't by the bath/shower.

Rob.

[Rob Nicholson]

Ahh right - I was thinking drier would make it stick easier on the ceiling.

Ahh this is the bit I wasn't sure about - how long to wait before trying to smooth off.

They are plasterboard screws which I think are okay.

Cheers, Rob.

[Rob Nicholson]

Thanks - will do.

Rob.

[Rob Nicholson]

Had a bash at this yesterday - not bad, although I say so myself, but a handful of low spots. I trained on a bit of plasterboard first but that was easier as it wasn't upside down, in a tight corner. Wish I'd done it before all the bathroom fittings went in :-) But in search of perfection, I think I'll do another skim over the top.

Is that okay? How long to wait before reskimming?

Thanks, Rob.